A positive electrode lithium supplement material of a lithium ion battery and a preparation method thereof
By preparing a positive electrode lithium replenishment material composed of conductive carbon element and lithium carbonate, the problem of active lithium loss during the initial charging process of lithium-ion batteries was solved, realizing high specific capacity and low cost commercial application, and avoiding the introduction of impurities and side reactions.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- XIAMEN UNIV
- Filing Date
- 2023-07-14
- Publication Date
- 2026-07-31
AI Technical Summary
The loss of active lithium during the initial charging process of existing lithium-ion batteries leads to a decrease in capacity and energy density. Existing pre-lithiation/lithiation replenishment methods have low capacity and are complex to prepare, and are prone to introducing impurities and side reactions.
A positive electrode lithium supplement material composed of conductive carbon elemental and nano-lithium oxide was prepared by ultrasonic dispersion of conductive carbon elemental and nano-lithium oxide in an alcohol solvent, followed by sand milling, drying, and calcination in a carbon dioxide atmosphere.
The prepared cathode lithium supplement material has high specific capacity, meets the needs of commercial lithium batteries, is simple to operate, low in cost, does not introduce impurities and side reactions, and is suitable for commercial applications.
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Figure CN117012965B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of lithium-ion battery lithium replenishment / pre-lithiation technology, and in particular to a positive electrode lithium replenishment material for lithium-ion batteries and its preparation method. Background Technology
[0002] Lithium-ion batteries (LIBs) have transformed our lives since their invention in the early 1990s. Now, LIBs dominate portable electronics and electric vehicles and are becoming a leading technology for grid energy storage. Further increasing their energy density is an urgent requirement to meet the growing demands of energy storage applications. However, the loss of active lithium during the initial charging process significantly reduces the capacity and energy density of LIBs due to the formation of a solid electrolyte interface (SEI) on the anode surface, a phenomenon particularly pronounced in high-energy-density batteries. To address this issue, pre-lithiation / replenishment, providing additional active lithium to the battery, has become a major direction in current battery technology development.
[0003] However, although the concept of pre-lithiation / lithiation supplementation has received some attention, its specific capacity is still relatively low, and the preparation methods are relatively complex, which may introduce impurities and side reactions. Summary of the Invention
[0004] Therefore, it is necessary to provide a method for preparing lithium-ion battery cathode lithium replenishment materials to solve the technical problem that existing materials cannot meet the lithium replenishment requirements of lithium batteries.
[0005] To achieve the above objectives, the present invention provides a method for preparing a positive electrode lithium replenishment material for lithium-ion batteries, comprising the following steps:
[0006] (1) Conductive carbon element and nano lithium oxide were ultrasonically dispersed in an alcohol solvent to obtain a dispersion solution;
[0007] (2) The dispersion solution obtained in step (1) is thoroughly milled and then dried;
[0008] (3) After the material dried in step (2) is ground evenly and compacted, it is ground again and then kept at 100-180℃ for 6-18h in a carbon dioxide atmosphere. After completion, the black powder obtained is the synthesized positive electrode lithium replenishment material.
[0009] In some embodiments, a transition metal oxide is also added in step (1) for dispersion.
[0010] In some embodiments, the transition metal oxide is an oxide of manganese, chromium, cobalt, or nickel.
[0011] In some embodiments, the ratio of the transition metal oxide to conductive carbon element is 1:1.
[0012] In some embodiments, the conductive carbon element is one or more of carbon black, graphene, or carbon nanotubes.
[0013] In some embodiments, the weight ratio of the conductive carbon element to nano-lithium oxide is 1:0.5-4.
[0014] In some embodiments, in step (2), the grinding conditions are 1200-2400 r / min for 12-24 h, and the drying conditions are 60-100 °C for 8-24 h.
[0015] In some embodiments, the alcohol solvent is methanol, ethanol, ethylene glycol, or propanol.
[0016] A positive electrode lithium replenishment material for lithium-ion batteries is prepared according to the above-mentioned method for preparing positive electrode lithium replenishment materials.
[0017] The above-mentioned technical solution has the following beneficial effects:
[0018] This invention obtains a cathode lithium supplement material composed of conductive carbon and lithium carbonate by calcining a material obtained from the dispersion, milling, and drying of conductive carbon and nano-lithium oxide in a carbon dioxide atmosphere. The prepared cathode lithium supplement material exhibits a high specific capacity (up to 724 mAh g / g). -1 This method can meet the lithium replenishment needs of almost all commercial lithium batteries. The cathode lithium replenishment material prepared by this method is simple to operate, has low synthesis cost, and possesses the potential for large-scale commercialization. This method can obtain cathode lithium replenishment materials that decompose at different sites by controlling the synthesis conditions and proportions. Compared with other existing lithium replenishment materials, the cathode lithium replenishment material prepared by this method will not introduce impurities and side reactions during practical applications, thus having the foundation for true commercialization after adaptation to cathode materials.
[0019] Terminology Explanation
[0020] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Unless otherwise specified, an element defined by the phrase "comprising..." or "including..." does not exclude the presence of additional elements in the process, method, article, or terminal device that includes said element. Additionally, in this document, "greater than," "less than," "exceeding," etc., are understood to exclude the stated number; "above," "below," "within," etc., are understood to include the stated number.
[0021] In this invention, "room temperature" and "normal temperature" refer to ambient temperature, ranging from approximately 10°C to approximately 40°C. In some embodiments, "room temperature" or "normal temperature" refers to a temperature ranging from approximately 20°C to approximately 30°C; in other embodiments, "room temperature" or "normal temperature" refers to a temperature ranging from approximately 25°C to approximately 30°C; and in still other embodiments, "room temperature" or "normal temperature" refers to 10°C, 15°C, 20°C, 25°C, 30°C, 35°C, 40°C, etc.
[0022] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples. Attached Figure Description
[0023] Figure 1 The XRD pattern of the positive electrode lithium replenishment material prepared in Example 1 was obtained at a scan rate of 10°min⁻¹ and a scan range of 10-90°.
[0024] Figure 2 The image shows the microstructure of the positive electrode lithium replenishment material prepared in Example 1, obtained under a field emission scanning electron microscope.
[0025] Figure 3The image shows the first charge-discharge test pattern of the positive electrode lithium replenishment material prepared in Example 1 using a LAND battery tester.
[0026] Figure 4 The positive electrode lithium replenishment material prepared in Example 1 was tested at 10°min. -1 XRD patterns before and after the first charge were obtained at a scanning rate of 10-90°.
[0027] Figure 5 The positive electrode lithium replenishment material prepared in Example 2 was tested at 10°min. -1 The XRD patterns obtained at a scanning rate of 10-90°.
[0028] Figure 6 The image shows the first charge-discharge test pattern of the positive electrode lithium replenishment material prepared in Example 2 using a LAND battery tester.
[0029] Figure 7 The positive electrode lithium replenishment material prepared in Example 3 was tested at 10°min. -1 XRD patterns obtained at a scanning rate of 10-90°.
[0030] Figure 8 The image shows the first charge-discharge test pattern of the positive electrode lithium replenishment material prepared in Example 3 using a LAND battery tester.
[0031] Figure 9 The positive electrode lithium replenishment material prepared in Example 4 was tested at 10°min. -1 The XRD patterns obtained at a scanning rate of 10-90°.
[0032] Figure 10 The image shows the first charge-discharge test pattern of the positive electrode lithium replenishment material prepared in Example 4 using a LAND battery tester.
[0033] Figure 11 The positive electrode lithium replenishment material prepared in Example 5 was tested at 10°min. -1 The XRD patterns obtained at a scanning rate of 10-90°.
[0034] Figure 12 The image shows the microstructure of the positive electrode lithium replenishment material prepared in Example 5, obtained under a field emission scanning electron microscope.
[0035] Figure 13 The image shows the first charge-discharge test pattern of the positive electrode lithium replenishment material prepared in Example 5 using a LAND battery tester.
[0036] Figure 14 The positive electrode lithium replenishment material prepared in Example 5 was tested at 10°min. -1XRD patterns before and after the first charge were obtained at a scanning rate of 10-90°.
[0037] Figure 15 The positive electrode lithium replenishment material prepared in Example 6 was tested at 10°min. -1 The XRD patterns obtained at a scanning rate of 10-90°.
[0038] Figure 16 The image shows the microstructure of the positive electrode lithium replenishment material prepared in Example 6, obtained under a field emission scanning electron microscope.
[0039] Figure 17 The image shows the first charge-discharge test pattern of the positive electrode lithium replenishment material prepared in Example 6 using a LAND battery tester.
[0040] Figure 18 The positive electrode lithium replenishment material prepared in Example 6 was tested at 10°min. -1 XRD patterns before and after the first charge were obtained at a scanning rate of 10-90°.
[0041] Figure 19 The positive electrode lithium replenishment material prepared in Example 7 was tested at 10°min. -1 The XRD patterns obtained at a scanning rate of 10-90°.
[0042] Figure 20 The image shows the microstructure of the positive electrode lithium replenishment material prepared in Example 7, obtained under a field emission scanning electron microscope.
[0043] Figure 21 The image shows the first charge-discharge test pattern of the positive electrode lithium replenishment material prepared in Example 7 using a LAND battery tester.
[0044] Figure 22 The positive electrode lithium replenishment material prepared in Example 7 was tested at 10°min. -1 XRD patterns before and after the first charge were obtained at a scanning rate of 10-90°. Detailed Implementation
[0045] To explain in detail the technical content, structural features, objectives, and effects of the technical solution, the following detailed description is provided in conjunction with specific embodiments.
[0046] Example 1
[0047] First, 1g of commercial conductive graphene and 1g of manganese oxide were dispersed in 500mL of ethanol solution. After ultrasonic and magnetic stirring for 1h, 0.5g of nano-lithium oxide was added. After ultrasonic and magnetic stirring for another 1h, the mixture was dispersed evenly and then transferred to a sand mill. After thorough sand milling (2000r / min, 20h), the mixture was dried (80℃, 24h). The dried material was then ground evenly and compacted (10MPa). After grinding evenly again, the material was transferred to a tube furnace and kept at 160℃ for 6h under a CO2 atmosphere. After cooling, the black powder was taken out, which is the synthesized positive electrode lithium replenishment material.
[0048] The prepared cathode lithium replenishment material was analyzed by XRD pattern, scanning electron microscopy, and first charge-discharge test results as follows: Figure 1-4 As shown.
[0049] From the appendix Figure 1-4 It can be seen that we have successfully synthesized a lithium carbonate composite carbon material as a positive electrode lithium replenishment material. Charging tests show that lithium carbonate can be decomposed at around 4V, yielding a 724mAh / g ionization rate. -1 High specific capacity.
[0050] Example 2
[0051] First, 1g of commercial conductive graphene and 1g of manganese oxide were dispersed in 500mL of ethanol solution. After ultrasonic and magnetic stirring for 1h, 1g of nano-lithium oxide was added. After ultrasonic and magnetic stirring for another 1h to ensure uniform dispersion, the mixture was transferred to a sand mill and thoroughly milled (2000r / min, 20h). Then, it was dried (80℃, 24h). The dried material was then ground evenly and compacted (10MPa). After grinding evenly again, it was transferred to a tube furnace and held at 160℃ for 6h under a CO2 atmosphere. After cooling, the black powder was taken out, which is the synthesized positive electrode lithium replenishment material.
[0052] The XRD pattern and first-cycle charge-discharge test results of the prepared cathode lithium replenishment material are as follows: Figure 5-6 As shown.
[0053] From the appendix Figure 5-6 It can be seen that we have successfully synthesized a lithium carbonate composite carbon material as a positive electrode lithium replenishment material. Charging tests show that lithium carbonate can be decomposed at 4.25V, yielding a 724mAh / g lithium carbonate solution. -1 High specific capacity.
[0054] Example 3
[0055] First, 1g of commercial conductive graphene and 1g of manganese oxide were dispersed in 500mL of ethanol solution. After ultrasonic and magnetic stirring for 1h, 2g of nano-lithium oxide was added. After ultrasonic and magnetic stirring for another 1h, the mixture was dispersed evenly and then transferred to a sand mill. After thorough sand milling (2000r / min, 20h), the mixture was dried (80℃, 24h). The dried material was then ground evenly and compacted (10MPa). After grinding evenly again, the mixture was transferred to a tube furnace and kept at 160℃ for 6h under a CO2 atmosphere. After cooling, the black powder was taken out, which is the synthesized positive electrode lithium replenishment material.
[0056] The XRD pattern and first-cycle charge-discharge test results of the prepared cathode lithium replenishment material are as follows: Figure 7-8 As shown.
[0057] From the appendix Figure 7-8 It can be seen that we have successfully synthesized a lithium carbonate composite carbon material as a positive electrode lithium replenishment material. Charging tests show that lithium carbonate can be decomposed at 4.5V, yielding a 724mAh / g ionization rate. -1 High specific capacity.
[0058] Example 4
[0059] First, 1g of commercial conductive graphene and 1g of manganese oxide were dispersed in 500mL of ethanol solution. After ultrasonic and magnetic stirring for 1h, 3g of nano-lithium oxide was added. After ultrasonic and magnetic stirring for another 1h, the mixture was dispersed evenly and then transferred to a sand mill. After thorough sand milling (2000r / min, 20h), the mixture was dried (80℃, 24h). The dried material was then ground evenly and compacted (10MPa). After grinding evenly again, the mixture was transferred to a tube furnace and kept at 160℃ for 6h under a CO2 atmosphere. After cooling, the black powder was taken out, which is the synthesized positive electrode lithium replenishment material.
[0060] The XRD pattern and first-cycle charge-discharge test results of the prepared cathode lithium replenishment material are as follows: Figure 9-10 As shown.
[0061] From the appendix Figure 9-10 It can be seen that we have successfully synthesized a lithium carbonate composite carbon material as a positive electrode lithium replenishment material. Charging tests show that lithium carbonate can be decomposed below 4.6V, yielding a 724mAh / g electrode. -1 High specific capacity.
[0062] Example 5
[0063] First, 1g of commercial conductive graphene and 1g of manganese oxide were dispersed in 500mL of ethanol solution. After ultrasonic and magnetic stirring for 1h, 4g of nano-lithium oxide was added. After ultrasonic and magnetic stirring for another 1h, the mixture was dispersed evenly and then transferred to a sand mill. After thorough sand milling (2000r / min, 20h), the mixture was dried (80℃, 24h). The dried material was then ground evenly and compacted (10MPa). After grinding evenly again, the mixture was transferred to a tube furnace and kept at 160℃ for 6h under a CO2 atmosphere. After cooling, the black powder was taken out, which is the synthesized positive electrode lithium replenishment material.
[0064] The prepared cathode lithium replenishment material was analyzed by XRD pattern, scanning electron microscopy, and first charge-discharge test results as follows: Figure 11-14 As shown.
[0065] From the appendix Figure 11-14 It can be seen that we have successfully synthesized a lithium carbonate composite carbon material as a positive electrode lithium replenishment material. Charging tests show that lithium carbonate can be decomposed at 4.6V, yielding a 724mAh / g ionization rate. -1 High specific capacity.
[0066] Example 6
[0067] First, 1g of commercial conductive graphene was dispersed in 500mL of ethanol solution. After ultrasonic and magnetic stirring for 1h, 0.5g of nano-lithium oxide was added. After ultrasonic and magnetic stirring for another 1h, the mixture was dispersed evenly and then transferred to a sand mill. After thorough sand milling (2000r / min, 20h), the mixture was dried (80℃, 24h). The dried material was then ground evenly and compacted (10MPa). After grinding evenly again, the material was transferred to a tube furnace and kept at 160℃ for 6h under a CO2 atmosphere. After cooling, the black powder was taken out, which is the synthesized positive electrode lithium replenishment material.
[0068] The prepared cathode lithium replenishment material was analyzed by XRD pattern, scanning electron microscopy, and first charge-discharge test results as follows: Figure 15-18 As shown.
[0069] From the appendix Figure 15-18 It can be seen that we have successfully synthesized a lithium carbonate composite carbon material as a positive electrode lithium replenishment material. However, after charging tests, a capacity of less than 500 mAh / g was obtained at 4.8V. -1 Specific capacity.
[0070] Example 7
[0071] First, 1g of commercial conductive graphene was dispersed in 500mL of ethanol solution. After ultrasonic and magnetic stirring for 1h, 4g of nano-lithium oxide was added. After ultrasonic and magnetic stirring for another 1h, the mixture was dispersed evenly and then transferred to a sand mill. After thorough sand milling (2000r / min, 20h), the mixture was dried (80℃, 24h). The dried material was then ground evenly and compacted (10MPa). After grinding evenly again, the material was transferred to a tube furnace and kept at 160℃ for 6h under a CO2 atmosphere. After cooling, the black powder was taken out, which is the synthesized positive electrode lithium replenishment material.
[0072] The prepared cathode lithium replenishment material was analyzed by XRD pattern, scanning electron microscopy, and first charge-discharge test results as follows: Figure 19-22 As shown.
[0073] From the appendix Figure 19-22 It can be seen that we have successfully synthesized a lithium carbonate composite carbon material as a cathode lithium replenishment material. However, after charging tests, a capacity of less than 200 mAh / g was obtained at 4.8V. -1 Specific capacity.
[0074] Example 8
[0075] First, 1g of commercial conductive graphene and 1g of manganese oxide were dispersed in 500mL of ethanol solution. After ultrasonic and magnetic stirring for 1h, 0.5g of nano-lithium oxide was added. After ultrasonic and magnetic stirring for another 1h, the mixture was dispersed evenly and then transferred to a sand mill. After thorough sand milling (2400r / min, 12h), the mixture was dried (100℃, 24h). The dried material was then ground evenly and compacted (20MPa). After grinding evenly again, the material was transferred to a tube furnace and kept at 180℃ for 6h under a CO2 atmosphere. After cooling, the black powder was taken out, which is the synthesized positive electrode lithium replenishment material.
[0076] Example 9
[0077] First, 1g of commercial conductive graphene and 1g of manganese oxide were dispersed in 500mL of ethanol solution. After ultrasonic and magnetic stirring for 1h, 0.5g of nano lithium oxide was added. After ultrasonic and magnetic stirring for another 1h, the mixture was dispersed evenly and then transferred to a sand mill. After thorough sand milling (1200r / min, 24h), the mixture was dried (100℃, 8h). The dried material was then ground evenly and compacted (10MPa). After grinding evenly again, the material was transferred to a tube furnace and kept at 100℃ for 18h under a CO2 atmosphere. After cooling, the black powder was taken out, which is the synthesized positive electrode lithium replenishment material.
[0078] Example 10
[0079] First, 1g of commercial conductive graphene and 1g of manganese oxide were dispersed in 500mL of ethanol solution. After ultrasonic and magnetic stirring for 1h, 0.5g of nano-lithium oxide was added. After ultrasonic and magnetic stirring for another 1h, the mixture was dispersed evenly and then transferred to a sand mill. After thorough sand milling (1200r / min, 24h), the mixture was dried (60℃, 24h). The dried material was then ground evenly and compacted (5MPa). After grinding evenly again, the material was transferred to a tube furnace and kept at 160℃ for 8h under a CO2 atmosphere. After cooling, the black powder was taken out, which is the synthesized positive electrode lithium replenishment material.
[0080] Although the above embodiments have been described, those skilled in the art, once they understand the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the above descriptions are merely embodiments of the present invention and do not limit the scope of patent protection of the present invention. Any equivalent structural or procedural transformations made using the content of the present invention's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.
Claims
1. A method for preparing a positive electrode lithium replenishment material for a lithium-ion battery, characterized in that, Includes the following steps: (1) Conductive carbon material and nano-lithium oxide were ultrasonically dispersed in an alcohol solvent to obtain a dispersion solution; (2) The dispersion solution obtained in step (1) is thoroughly milled and then dried; (3) After the material dried in step (2) is ground evenly and compacted, it is ground again and then kept at 100-180℃ for 6-18h in a carbon dioxide atmosphere. After completion, the black powder obtained is the synthesized positive electrode lithium replenishment material.
2. The method for preparing the positive electrode lithium replenishment material according to claim 1, characterized in that, In step (1), transition metal oxides are also added for dispersion.
3. The method for preparing the positive electrode lithium replenishment material according to claim 2, characterized in that, The transition metal oxide is an oxide of manganese, chromium, cobalt, or nickel.
4. The method for preparing the positive electrode lithium replenishment material according to claim 2, characterized in that, The ratio of the transition metal oxide to the conductive carbon element is 1:
1.
5. The method for preparing the positive electrode lithium replenishment material according to claim 1, characterized in that, The conductive carbon element is one or more of carbon black, graphene, or carbon nanotubes.
6. The method for preparing the positive electrode lithium replenishment material according to claim 1, characterized in that, The weight ratio of the conductive carbon element to nano-lithium oxide is 1:0.5-4.
7. The method for preparing the positive electrode lithium replenishment material according to claim 1, characterized in that, In step (2), the grinding conditions are 1200-2400 r / min for 12-24 h, and the drying conditions are 60-100 ℃ for 8-24 h.
8. The method for preparing the positive electrode lithium replenishment material according to any one of claims 1-7, characterized in that, The alcohol solvent is methanol, ethanol, ethylene glycol, or propanol.
9. A positive electrode lithium replenishment material for lithium-ion batteries, characterized in that, It is prepared by the method for preparing positive electrode lithium replenishment material according to any one of claims 1-8.